Author	[Modern View]
tracman 08-02-2012 15:35:22 142.52.81.12 Report to Moderator	Gentlemen, what is difference between the A8NN12250A and the A8NN12250B ballast resistor? What would be the difference between the 6 Volt 2N and the 6 Volt 8n coil? The conversion on my 8N front mount to 12 volts is lacking the ballast resistor. A 0.8 ohm resistor was added instead and the tractor has been running for a couple of years with that arrangement. Probably luck I guess. I would like to add a ballast resistor and maybe a new coil as well. [Reply]   [No Email]
soundguy 08-02-2012 16:14:59 107.41.175.12 Report to Moderator	Re: 8N ballast resistor in reply to tracman, 08-02-2012 15:35:22   ditto what bruce and jmor said. you got lucky that your coil is of good enough quality that it is working with the supplied resistor... and if running 2ys with no cracked coil or roasted points.. probably ok to keep running it. if you ever change coils.. hit a correct setup at that time..   [Reply]  [No Email]
tracman 08-03-2012 10:44:45 142.52.81.12 Report to Moderator	Re: 8N ballast resistor in reply to soundguy, 08-02-2012 16:14:59   Thanks everyone for responding. I will check my points and see how they are holding up. If they look cooked I will add some resistance in to drop the current to 4.0 amps at 14 volts and see how that plays out. tracman   [Reply]  [No Email]
soundguy 08-03-2012 15:37:23 107.41.43.217 Report to Moderator	Re: 8N ballast resistor in reply to tracman, 08-03-2012 10:44:45   god deal.. post back what you find   [Reply]  [No Email]
BillM (OH) 08-02-2012 20:54:11 173.81.81.180 Report to Moderator	Re: 8N ballast resistor in reply to soundguy, 08-02-2012 16:14:59   I got my first 8N ('48) about 9 years ago, and just ran the snot out of it mowing 8 acres or so for 4 years. When I finally decided to upgrade the wiring, etc., and found NO ballast resistor in the ignition circuit - it was still there but wiring had been cut and bypassed - could not believe it didn't melt the coil in 4 years of hard running. Tractor was pretty much a beater when I got it and has been retired (for now) as I got my next ('50) 8N, that was dad's, from my brother when he picked up a couple of 3000's for next to nothing. I am going to decide what to do with the '48 one of these days, but expect a rebuild will be in order just based on oil pressure and hard starting - compression test will likely tell the story - been afraid to run one as yet, as I don't have the $$$$ for a rebuild, and it wouldn't be worth it anyway.   [Reply]  [No Email]
soundguy 08-02-2012 21:47:04 184.4.151.135 Report to Moderator	Re: 8N ballast resistor in reply to BillM (OH), 08-02-2012 20:54:11   was it 6v or 12v?   [Reply]  [No Email]
BillM (OH) 08-04-2012 18:42:03 173.81.81.180 Report to Moderator	Re: 8N ballast resistor in reply to soundguy, 08-02-2012 21:47:04   Both my N's are 6V. I did convert the 861 up on the NY farm to 12V years ago as Dad had the tractor outside and it was not used much, so the starter shaft would get a light coat of rust and 6V would not throw the Bendix until starter was pulled and shaft cleaned up squeaky clean. Got tired of pulling the starter, converted to 12 V and never had another problem throwing the Bendix - has worked fine ever since.   [Reply]  [No Email]
Bruce (VA) 08-02-2012 16:08:43 24.125.80.178 Report to Moderator	Re: 8N ballast resistor in reply to tracman, 08-02-2012 15:35:22   The difference is the mounting bracket. The B is for a 9 or 2N. The OEM ballast resistor changes value as it heats up. A fixed resistor does not. In a perfect world, your 12 volt convrsion would be better off w/ a "6v" coil, OEM ballast resistor AND an additional resistor in the circuit that limited coil current to less than 4 amps. That way, the additional resistor will act as a heat sink & the coil will operate at a lower temp. To do that, you need to measure the internal resistance of the coil in order to determine the appropriate value of the additional resistor. Most folks find it easier to just use the OEM ballast resistor & a "12v" coil because a "12v" coil usually has at least 2.5 ohms of internal resistance. 50 Tips   [Reply]  [No Email]
JMOR 08-02-2012 16:07:40 99.105.24.57 Report to Moderator	Re: 8N ballast resistor in reply to 1951 8N, 08-02-2012 15:35:22   Quoting Removed, click Modern View to see #1-If it ain't broke, don't fix it......or it may wind up broke! #2-If I recall correctly, the difference is in the mounting holes.   [Reply]  [No Email]